Electrochemical machining, electrochemical polishing, electrochemical through-mask etching, and electrochemical deburring are all examples of electrochemical material removal processes whereby metal is removed from a workpiece via an electrochemical reaction.
In electrochemical machining, a workpiece and a geometric shape function as electrodes. For example, the workpiece is typically an anode and the geometric shape is typically a cathode or tool electrode. The geometric shape can be a mirror image of a desired shape of the workpiece. During operation, material is typically removed from the workpiece by an anodic electrochemical reaction. An example of an application that employs electrochemical machining processes is in the manufacturing of gun barrels whereby the internal surface is rifled.
Other examples of processes that use an anodic electrochemical reaction to modify a workpiece include electrochemical polishing, electrochemical through-mask etching, and electrochemical deburring.
Electrochemical material removal has strong utility as a manufacturing technology for fabrication of a wide variety of metallic parts and components. Electrochemical machining has numerous advantages relative to traditional machining, for example, applicability to hard and difficult to cut materials, low tool wear, high material removal rate, smooth bright surface finish, and/or production of parts with complex geometry.
Compared to mechanical machining processes where material is typically removed by mechanical cutting and thermal machining processes where material is typically removed by electric discharge machining or laser cutting, electrochemical material removal is a non-contact machining process and typically does not result in a mechanically damaged or thermally damaged surface layer on the machined work piece.
While electrochemical material processes are particularly noted for resulting in a typically superior surface finish compared to mechanical machining processes, the material removal rates are typically less than mechanical machining processes.
Voltage technologies include electrochemical grinding processes that combine mechanical grinding with an anodic electrochemical reaction. For example, in electrochemical grinding a grinding wheel operates as mechanical grinder and a cathode. Electrochemical grinding processes can be advantageous over mechanical grinding alone and electrochemical processes alone because it increases removal rates typically associated with the mechanical grinding, and improves surface finishes typically associated with anodic electrochemical reactions.
During electrochemical grinding, typically, a larger portion of material is removed from the workpiece by an anodic electrochemical reaction (e.g., 90%) and a smaller portion of material (e.g., 10%) is removed from the workpiece by mechanical grinding. Voltage electrochemical grinding can provide surface finishes, typically in the 9 to 20 μinch Ra. For many machining applications improved surface finishes with greater than 1 μinch Ra are required. For example, many military machines (e.g., helicopters or gun systems) are manufactured with new materials that require a high surface finish.
Thus, there is a continued need to maintain and even improve the rapid material removal rates associated with mechanical grinding or electrochemical grinding and obtain even better surface finishes such as those associated with electrochemical machining of <1 μinch Ra.